Boston — Senate candidate Elizabeth Warren, embroiled in controversy over whether she sought to advance her academic career by representing herself as a minority, has for the first time said she told two universities that she had native American heritage.

But Professor Warren said she provided the information to Harvard and the University of Pennsylvania after she was hired by those institutions. And she noted, as she has done previously, that people who played prominent roles recruiting her for law school teaching positions "have said unequivocally they were not aware of my heritage and that it played no role in my hiring."

Warren, a Democrat known for taking a public stand against big Wall Street banks in the wake of the financial crisis, is trying to unseat Sen. Scott Brown (R) of Massachusetts.

Prior to Wednesday's statement, Warren had acknowledged only that she listed herself as a minority in a national directory of law school professors, during years when she was at Penn (starting in the 1980s) and Harvard (starting in the early 1990s).

Warren grew up in Oklahoma, where Cherokee ancestral ties are not uncommon. But she has provided no documentation to confirm her heritage.

"Growing up, my mother and my grandparents and my aunts and uncles often talked about our family’s Native American heritage," Warren said in the statement, which the Globe released online. "As a kid, I never thought to ask them for documentation – what kid would? – but that doesn’t change the fact that it is a part of who I am and part of my family heritage."

The newspaper reported that both universities listed a native American female on their law school faculty. Prestigious law schools at the time were under pressure to diversify their faculty to include more women and racial minorities.

At Penn, "an internal publication drawing on statistics from the university’s federal affirmative action report" included that listing for 1991, 1992, and 1994, the Globe reported. The paper said Harvard law school records listed a native American female when Warren was a visiting professor during the 1992-93 school year, and "begin to list one again in 1995-96, when she returned to Cambridge as a tenured professor."

Among the lingering questions is whether Warren knew the prevailing definition of "native American" when she claimed minority status. The Globe article says that "federal statistics like those in the Harvard records,... rely on a definition of 'Native American’ that requires both ancestry and an official affiliation with a tribe or community."

Warren doesn't appear to fit that definition.

Another question is whether Warren hoped that, by making herself known as a minority, her career would be advanced.

Her new statement says she provided information about her heritage to the universities "at some point after I was hired by them." But once she was presenting herself as native American to Penn, it's possible that people at Harvard would view her that way.

Warren's statement this week comes as the state's Democratic Party prepares to hold its convention this weekend. At stake there is whether Warren will face a challenger on the ballot when the Democratic primary is held in September.

Another challenger, attorney Marisa DeFranco, will go on the ballot if she wins 15 percent of delegates at the convention.